长期秸秆还田对黄土旱塬区土壤肥力的影响

Effect of Long-term Straw Returning on Soil Fertility in Dryland of Loess Plateau

采用长期定位试验方法,研究分析了秸秆还田对黄土高原旱塬地土壤肥力的影响。结果表明:经过24a的长期施肥,表层土壤碱解氮、有效磷含量呈下降趋势,土壤有机质、全氮、全磷均呈现出不同程度的富集趋势;秸秆与化肥配合施用时土壤有机质、全氮、全磷的富集效应较明显,长期施用秸秆能加快土壤有机质转化速率,降低有机质的氧化稳定性,提高土壤肥力。长期秸秆还田对剖面养分的影响表现为随着土层的加深,养分含量呈现出减少趋势,有机质和全氮的的变化趋势基本相同,全磷含量在耕层较高,在80 cm土层形成最低值。

Soil samples from the long-time experiment in dry highland of Loess Plateau were used to analysis the effect of extensive straw returning, the results show that the available nitrogen and phosphate have a low trend, but the soil organic matter, total nitrogen and phosphate take on enrichment in some extent under twenty four years long time supply, moreover, the combined chemical fertilizer and straw returning soil enrichment is very obvious in soil horizons. At the same time, straw can increase the ratio of organic matter changing, significantly reduce soil readily oxidizable organic matter, finally the high fertilization is receive. The effect of soil nutrient using fertilize in profile show that the content of soil nutrient take on low trend, the change trend of the soil organic matter and total nitrogen is same. The content of total phosphate is high in arable layer, but low peak appear in 80 cm.